An investigation into the reaction and breakdown products from starting substances used to produce food contact plastics

Food packaging materials made of plastics may contain substances that are not used intentionally and do not appear in lists of permitted ingredients. These substances may be present as impurities in the starting materials used to make the plastic or as reaction or decomposition products formed during polymerisation to make the plastic or during thermal processing of the plastic to make the packaging. These substances are commonly referred to as NIAS (non-intentionally added substances). The compliance of food contact plastics with existing legislation should take into account both (a) known ingredients and (b) their impurities, reaction products and breakdown products. To date most studies have concentrated on the former and have largely neglected the latter.